Inspections on Aircraft Structures

I was reading an article written by Kevin Cowherd today on TheStar and I can’t help but be amused at some of the points that he wrote in his article. I will give him the benefit of the doubt because he admits that he is not an expert in aviation. But just to clear some things up.

In this article, the focus was on cracks on an aircraft. Based on the article, Southwest Airlines was fined US$10.2 million for not doing mandatory structural inspections. If you remember Aloha Airlines, cracks on the fuselage caused the whole top portion of the fuselage to rip off.

Aloha Airlines Flight 243. 1988.

Inspections on aircraft structure is one of the mandatory task carried out when the aircraft is in the hangar for maintenance. Basically checks are made to ensure all structures are fastened properly, no cracks, no missing pieces, no corrosion. Did I mention checking for cracks?

Now when the aircraft is in the hangar, cracks can never escape a normal structure inspection. Cracks are just too big to be missed. If you can see a crack while boarding the plane, you’re probably not going to get to your destination.

Anyways, here are some of the points that I don’t agree with:

“…you could have the crew expend some of the energy checking the plane for cracks from now on.”

Pilots actually do a walk-around check before every flight to make sure everything is in order. They check things like wheels, brakes, general condition of flight control surfaces, any missing screws or panels. It’s a very quick check. They don’t have time to check the plane all over for cracks. That would take too much time. Checking for cracks takes days, not 5 minutes. And you need special scaffoldings to reach the top fuselage, the tail, and the top of the wings. Special tools are also required sometimes, like inspection mirrors and a good torch light. It just isn’t practical to ask the pilots and the stewardess to do it. They might miss the big cracks on the top of the fuselage, for example.

“…we’d gladly put up with a short delay while someone walks around the plane and makes sure the tail assembly isn’t about to pull away in mid flight.”

Line engineers do that. And like I’ve said, pilots do that as well. But they cannot check the whole plane. They won’t know if the tail assembly would pull away in mid flight unless they open up the access panels on tail section and inspect the attachment bolts. They have just 45 minutes of transit time to refuel, do a quick walk-around check, unload and load baggages, load food, do lavatory servicing if needed and sometimes change tyres. All in 45 minutes. There isn’t time to inspect every inch of the aircraft. The proper support equipment is not there as well. That’s why structural inspections are done in hangars during maintenance. Engineers can then throughly sweep the plane and find any defects and rectify them before they become too serious. In hangars, various other types of inspections are done too. Like ultrasonic inspection, magnetic particle inspection, dye penetrant inspection, x-ray inspections. These inspection methods can show what the naked eye cannot see.

“…over 99% of inspections were completed, according to documentation.”

Gary Kelly, CEO of Southwest must have made a mistake. An aircraft with 99% of MANDATORY inspections done cannot be released for service. Unless he’s suggesting that the inspections were not done properly. In the aviation industry, we have very strict rules and requirements to follow. Every job completed must have the proper documentation. They will know if someone did not do their inspections.

“…it’ll (Southwest) be checking for cracks like nobody’s business from now on, with dozens of employees swarming over every plane.”

Not everyone needs to be mobilized to check for cracks. Inspections during maintenance in hangar is more than enough to detect cracks or signs of it. Engineers go through the plane very throughly so there is very little to be worried about. If they can’t find that crack, no one else can. Because experience really counts. They know where highly stressed parts are and where cracks are likely to appear. Trust them on this. And checking for cracks on the outer structure (fuselage, wing surfaces) is not enough. A cracked wing spar cannot be seen from the outside, but it can cause the wings to detach from the plane. That is why planes are dismantled and various inspection tools are used when they are inspected in hangars.

“…I wouldn’t be surprised if Gary Kelly himself was out there on the tarmac these days doing some inspections.”

I would be. He could just hire someone else to do the job for him. Engineers on the tarmac can probably spot the crack faster. And furthermore, he probably don’t have the required license to sign for the inspection.

“99% isn’t all fine” is an article written by someone who flies on a plane, not someone who works on the plane. I feel that the article itself undermines the effort put in by the maintenance and engineering staff to ensure the safety and airworthiness of the aircraft. We all take our jobs seriously. Because unlike doctors, if we don’t do our jobs properly, more than one person will die.

Can you sleep at night knowing you’ve killed more than 100 people with one mistake? Continue reading

Polls Summary

I’ve been running a lot of polls on this site and it is now the time to summarize the results to see the big picture. Before that, I apologize for not blogging because of exams.

The site layout change was done because I felt that the old one was too old and I want something simpler and easier to use. This new layout incorporates larger fonts, less sidebars, cleaner layouts. I feel that it makes reading easier. But if you have any comments about it, or would like to see some changes, I would like to hear from you. Drop me some comments below.

This poll has mixed reactions. There are of course many ways that we can save our planet. It would be unfair to say that just one of the above can save our earth from destruction. In fact, I recently attended a seminar on the environmental impacts of the airline industry. I have some notes but I have not have the time to compile them. Expect them to be out soon.

With almost everyone using a broadband line now, there’s little reason to heavily compress pictures. Therefore I have been using higher quality pictures with less compression and bigger file sizes. The downside is that it’s taking a toll on my bandwidth. Time for an upgrade.

There’s no doubt that consumers will embrace GPS when it becomes cheaper because it is indeed very useful when going to places you’ve never been to. Last weekend, for the first time I heard about Jalan Kapar Batu 1 in Klang, and in an hour, I was there with the help of the GPS. Before this, my preferred method was reading the map.

The outcome of this poll was expected. Because I have my site stats. But still, it’s amazing to see Firefox overtaking Internet Explorer in the span of a few years. Hopefully memory issues will be solved when Firefox 3 is released.

So there you have it. The results of the polls. I have a new poll up by the way. Is Facebook really taking over the social networking scene? Vote and you shall be heard. No phantom voters here please. Continue reading